(1) Field of the Invention
The present invention relates to an image forming apparatus, such as a copying machine or a printer, and a monitor system which can monitor the frequency of image formation performed by different groups of users.
(2) Description of the Prior Art
Copying machines are often shared by sections in an organization such as a firm. In such case, the number of copies made by each section which uses the copying machines is monitored for budget control and other purposes.
Conventionally, to monitor the number of copies made by each section, section numbers which indicate each section, and secret identification codes which are allocated to each section (hereinafter called "IDs") are registered beforehand After a user inputs the ID of his/her section, the user is permitted to make copies, with the number of copies made by the user's section being counted.
For this purpose, a memory in a conventional copying machine is provided with a section monitor storage unit for storing the number of copies made by each section and a section monitor table for storing IDs which are allocated to each section. For instance, the section monitor storage unit may have 100 storage areas, each section number may correspond with the address numbers (001-100) in the storage unit, and the number of copies made by a section indicated by an address number may be stored in the corresponding address area. On the other hand, in the section monitor table, IDs which are assigned to each section and the address numbers which correspond with each section in the section monitor storage unit are recorded, with the IDs and the address numbers being related to each other.
In such a copying machine, a user who wishes to make copies inputs the ID of his/her section and is permitted to make copies only when the ID is registered in the section monitor table. An address corresponding with the ID is read from the section monitor table and the number of copies made by the user after receiving permission is added to the number stored in the storage area of the read address number.
With the copying monitor method described above, users are permitted to make copies after a certain ID is inputted. The number of copies is stored in a storage area of an address number that matches a section number which corresponds with the ID in the section monitor storage unit. As a result, the number of copies made by each section can be easily monitored.
In the monitoring method described above, memory addresses are described as corresponding with section numbers. This means that in a large firm with 1000 or more sections, it is necessary to provide as many storage areas in the section monitor storage unit and in the section monitor table as there are sections in the entire firm.
However, it seems unrealistic that a specific copying machine would be used by 100 or more sections even if the total number of sections in the firm is 1000, because each section or each group of sections will usually have its own copying machine. If each copying machine is provided with storage areas for 1000 sections regardless of such reality, a large amount of memory will go to waste. Also, should the number of sections happen to exceed 1000, the memory will need to be expanded to register the excess sections. These things are problematic.
To avoid such problems, the storage area of each copying machine may be given 100 address numbers, with sections which are likely to use the copying machine being listed and the section numbers being assigned in each copying machine separately. The number of copies corresponding with each section may be recorded in an address number in accordance with a section number assigned in each copying machine.
By doing so, however, the same address number of each copying machine is assigned to different sections. For instance, the address number 001 of the copying machine A may be assigned to the general affairs department and the address number 001 of the copying machine B may be assigned to the accounts department. This can cause confusion when the number of copies made by each section is totaled for all of the copying machines.
In the case where the number of copies made by each section is monitored by a host computer which is wired up to the plurality of copying machines, it is necessary to register the address numbers in each copy machine for each section, making the totaling process extremely complex.